Various materials, such as metals, are plated to enhance performance properties. For example, steel is commonly plated with chromium (chrome), such as hexavalent chromium or trivalent chromium, to increase hardness, enhance wear-resistance and/or improve lubricity. Chrome plating is also used for purely aesthetic purposes. Therefore, chrome plated structures can be found in various industrial applications, such as in the aerospace and automotive industries.
Chrome plating has a cracked microstructure comprised of a fine lattice of microcracks having no definite or repeating pattern. These microcracks may facilitate rapid corrosion of the underlying substrate. Therefore, various techniques have been developed in an attempt to inhibit corrosion of chrome-plated structures.
As one example, additional plating layers, such as a layer of nickel plating, are used to improve the corrosion resistance of chrome-plated structures. However, additional plating processes are capital intensive, time consuming, and generate additional byproducts that require special handling and disposal.
As another example, chrome-plated structures are impregnated with a polymer to improve corrosion resistance. Specifically, styrene monomer resin is used to impregnate chrome-plated structures using a vacuum impregnation process, followed by an alkaline cleaning step and a resin cure step. However, polymer impregnation is very capital intensive, messy, exacting and time consuming.
As yet another example, chrome-plated structures are painted with a hexavalent chromium-based primer. After a short dwell time, excess primer is wiped away, requiring particular attention to materials handling and disposal.
Accordingly, those skilled in the art continue with research and development efforts in the field of corrosion inhibition.